Evolution of the median properties of fossil and control groups. The left plots correspond to the sample of fossils and controls defined using the ΔM₁₂ magnitude gap, while the right plots correspond to the definition based on the ΔM₁₄ magnitude gap. Panels in the first row show the evolution of the r-band absolute magnitude of the brightest galaxy of the groups; the second row shows the absolute magnitude of the second and fourth brightest galaxies; the third, fourth, and fifth rows show the evolution of the r-band absolute magnitude gap between the brightest and the second, third, and fourth brightest galaxies, respectively, the dashed horizontal lines correspond to the thresholds used to define fossil groups; the sixth row shows the stellar mass of the brightest galaxy, and the last row shows the evolution of the stellar mass of the brightest galaxy normalised to its final stellar mass. Error bands are the semi-interquartile ranges.